A tailstrike can result in extensive damage to an aircraft. A tailstrike is said to occur when the tail section of an aircraft strikes the ground, either on takeoff (when the aircraft climbs too rapidly) or landing (when the nose is raised too much during flare).
In addition to readily-apparent structural damage, a tailstrike may result in unseen structural faults that can lead to a delayed fracture. For this reason, aircraft that suffer a tailstrike typically undergo a variety of tests to ensure reliability for further flight. The subsequent loss in airtime may result in lost revenues for the aircraft operator.
Tailstrikes are particularly common with transport planes. A possible reason is that a transport plane's weight can vary substantially between flights, which may result in substantial variances in the aircraft's responsiveness to pitch rotation. This, in turn, may result in crew under/overestimating pitch rotation, which can lead to a tailstrike.
Tailstrikes are also common when a pilot is familiar with lighter cargo—passenger flights, for example—and then begins operating heavier flights. An aircraft with a heavier cargo may have a different sensitivity to pitch rotation commands. This change in sensitivity may result in the inexperienced pilot under/overestimating pitch rotation.
Some known solutions to tailstrikes include adding a skid or wheel in the rear of the aircraft to prevent damage. This has limited efficacy, however, because the skids only reduce the impact of the strike; structural damage can and does occur.
Some other known solutions include offering a warning to the crew of an impending tailstrike. Traditionally, such tailstrike warnings are determined by analyzing the aircraft pitch angle. This has proved an unsatisfactory solution, however, because pilots typically do not rely on pitch angle for understanding fight conditions. Because pilots do not rely on pitch angle for understanding flight conditions, pitch angle based information can be disorienting, especially during takeoff and landing when the pilot is absorbing and processing large quantities of critical information. As a result, analyzing pitch angle for tailstrike warnings has proven to have limited effectiveness in combating tailstrikes.